My '84 7-passenger has ECU behind left taillight and Idle Stabilizer and ICM
are on left side of engine compartment just ahead of coil.

Congratulations on the reverse engineering efforts.

John
----- Original Message -----
From: "jon" <jon@KENNEKE.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Wednesday, December 20, 2006 9:23 PM
Subject: Re: More AFM/ECU reverse engineering results coming

> All of the vanagons I have seen have the ECU under the rear seat, and the
> idle stabilizer behind the tail light.
>
> No big heat problems with the ECU that I can think of. But, the idle stab.
> may want to be near the ambient temp of the vanagon.
>
> I'll have to look into that more when I get into reverse engineering the
> idle stab.
>
> Jon
>
>
>
> On Wed, 20 Dec 2006, ------------------------- wrote:
>
>> "What confuses me if why they didn't simply put that functionality in the
>> ECU???"
>>
>>
>>         VW  Did in the Golf and Jetta 88-92.  I'm assuming there is a
>> heat problem
>> with this in the Vanagon, because of its location.
>>
>>
>>
>> jon wrote:
>>
>> >I've taken apart an early (pre-86) idle stabilizer. It appears to be a
>> >pulse shaping/delay unit. It is inserted in between the hall sensor and
>> >the ECU. If fact, you can simply unplug both connections, and plug them
>> >together to run without. It adjusts the timing based on idle RPM, I
>> >assume.
>> >
>> >The later units are much more complex, judging by looking at Bentley.
>> >One
>> >of these days I'll reverse engineer one of those. Anyone have a dead one
>> >they want to send me?
>> >
>> >What confuses me if why they didn't simply put that functionality in the
>> >ECU???
>> >
>> >Jon
>> >(The Reverse Engineer)
>> >
>> >On Wed, 20 Dec 2006, John Rodgers wrote:
>> >
>> >
>> >
>> >>Sounds good to me. Anyone working on reverse engineering that idle
>> >>stabilizer control module??
>> >>
>> >>Regards,
>> >>
>> >>John Rodgers
>> >>88 GL Driver
>> >>
>> >>jon wrote:
>> >>
>> >>
>> >>>I have made great progress in reverse engineering AFMs, ECUs and other
>> >>>funny business in the Digifant injection system. It's classic 80's
>> >>>embedded CPU technology.
>> >>>
>> >>>I pulled apart a bad ECU to use part from to build a "sniffer". It was
>> >>>interesting to see how they did it. Here is a quick explanation:
>> >>>
>> >>>The "brain" is a standard 6803U4PV. It's a common 80's embedded
>> >>>microcontroller. Not sure what the differences are in the U4PV
>> >>>version,
>> >>>because I can't find a datasheet on the 'net. On the CPU daughterboard
>> >>>there is also a Parallel Interface Adapter, some glue logic, and a
>> >>>2732B
>> >>>EPROM. The version label on this one is "FAEB02 02. 02". Anyone have
>> >>>an
>> >>>ECU open, and can tell me what their's says?
>> >>>
>> >>>On the main board, the interesting semiconductors are a Toshiba
>> >>>TA7900S
>> >>>regulator/watchdog with PNP shunt transistor (BD438). Across the heat
>> >>>sink
>> >>>is also a BD647 NPN Darlington, a Motorola TE2369 (Which I can't find,
>> >>>probably a house number. Anyone know what this is?), and a BT151-500R
>> >>>Thyristor. The big chip near the center is an Analog to Digital
>> >>>converter.
>> >>>Add to that some small signal transistors, couple of op
>> >>>amp/comparators,
>> >>>and finally a "Peripheral Clamping Array" on the input to the PIA/CPE
>> >>>to
>> >>>condition signals.
>> >>>
>> >>>These ECUs make magasquirts look simple. ;)
>> >>>
>> >>>More on AFM spring adjustments in a bit.
>> >>>
>> >>>Jon
>> >>>
>> >>>
>> >>>
>> >>>
>> >>>
>> >
>> >
>> >
>>
>